Biology II Exam 2 Study Guide
Biology II Exam 2 Study Guide BIO 1144
Popular in Laboratory
Popular in Department
This 16 page Study Guide was uploaded by Rocket on Friday February 19, 2016. The Study Guide belongs to BIO 1144 at Mississippi State University taught by Thomas Holder in Spring 2016. Since its upload, it has received 61 views.
Reviews for Biology II Exam 2 Study Guide
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/19/16
Exam #2 Plant Growth Indeterminate Growth: Continual growth until Death Increase of Cell Number/Size ❖ Sexual Cycle of Angiosperms Alternation of Generations between Diploid (2n) and a Haploid (1n) Sporophyte (2n) Gametophyte (1n) Spore producing platform Gamete producing platform Macroscopic Microscopic Dominant Part (mostly) 27 cells in size Produces flowers/fruits Pollen in Male + Embryo Sac in Female Key Terms: Meiosis→ changes chromosomes number by ½, changes in generation Syngamy → will restore chromosomes number , also causes change in generation Plant Organs: Roots, Leaves, Stems combine into Shoots Development due to rapid production of cells in Mitosis+Cytokinesis ➢ Primary growth (1 °) Elongation of plant organs All Plants have Primary tissues resulting from growth ❖ Primary Tissue: 1 ° Xylem: Conducting tissue, water, minerals 1 ° Phloem: Conducting tissue, food, solutes Epidermis: outermost tissue Parenchyma: storage tissue of food/water Collenchyma : protection of plant organs for support in elongated Sclerenchyma : protection of plant organs for support in non elongated plant organs ❏ Secondary Growth Expansion of plant organs Only in Root+Stems Producing “woody tissue” NOT IN ALL PLANTS 2 Major Groups of Angiosperms: Monocots : Primary growth Dicots: All primary growth, mostly secondary growth ● Tips of Root + Shoot Meristems: cells constantly divided for plant growth + Apical (tips) Meristem (AM) RAM (Root AM) SAM (Shoot AM) Lateral Meristems: “rings” in stems or root, in secondary growth cause expansion in increased diameter (root/stem) Roots Function: Anchorage Storage of food and water Absorb water/ minerals of soil VCyl: Vascular Cylinder(inside endodermis) : where xylem and phloem are located Shoot 1° = Elongation Inside Bud is the SAM (Shoot Apical Meristem) Node : any point along stem where leaf, bud, or branch arises Internode : region between 2 nodes, elongation occurs within these Stem: region where all elongation occurs Dicot Leaf Monocot Leaf Net Vernation Parallel venation (no branching) Stems 1° Growth Leaf and Stems develop differently VB= Vascular Bundle Monocots Dicots 1° rowth (elongation) 1° growth (elongation) Scattered VB 2°Secondary growth (expansion) Ringed VB (also pith and cortex) Dicot 1st Growth VC+CC produce “rings” of secondary tissues inside/outside of the cambium ring VC+CC are lateral meristems = 2°growth Inside Cell = Secondary xylem(wood) Outside cell = Secondaryphloem (inner bark) CC Inside Cell/Outside Cell =eriderm outer bark) function as protection, starts growing late first year Dicot 2°Growth Stem after 3 years of secondary growth, begins LATE in first year Comparison Between Plant Organs ❖ Growth Leaves: 1° growth Dicot: Net Venation Monocot: Parallel Venation Roots: Monocots: 1° growth Dicots: ° + 2growth Stems: Monocots: 1° growth Dicots: ° + 2° growth ➢ Layout Roots: Endodermis Pericycle Monocots: Pith + Cortex Dicot: Cortex (Xylem at core) Stems: Monocot: Scattered VB’s, no pith or cortex Dicot: Pith + Cortex, VB’s in ring pattern 1° Growth= Elongation (Apical Meristems: SAM + RAM) 1°tissues 2° Growth = Expansion (Vascular and Cork Cambium) Stem and Roots only 2°tissues Hormones “chemical messengers” Transported in Phloem tissues, Require energy (ATP) Interact with external environmental factors ex. temp, moisture, soil Controls plant growth, seed germination, flowering, fruiting, shedding leaves, color loss, changes in color Growth inhibiting mostly in fall/winter (slow growth) Growth promoting mostly in spring/summer (kick in growth) Growth promoting ❏ Auxins Produced in shoot tips, leaves, fruits, and seeds, not produced in roots +Effects: Promotes cell/stem elongation Promotes stem expansion Promotes development of fruit Inhibits bud development Inhibits theabscission ❖ Cytokinins Produced in seeds, fruits, and roots +Effects: Promotes Mitosis+Cytokinesis, production of new cells as quickly as possible Promote development of buds Inhibit leaf senescence: loss and breakdown of chlorophyll in leaves 3. Gibberellins ( ibberellic Acid) Produced throughout plant, but highly concentrated within seeds Effects: Promote stem elongation Promote cell division Promote the breakdown of food preserves, in germinating seeds Corn seed Aleurone Layer (outer layer + stored food) Embryo Stored food (mostly starch) Food Breakdown 1. Water intakes causes cracking of seed coat 2. Embryo secretes Gibberellins 3. Gibberellins transported to Aleurone Layer 4. Aleurone layer secretes enzyme ( αamylase) which breaks the bonds of starch molecules 5. Starch→ Glucose→ Cell respiration→ yields ATP for growth * Advantage of seed plants: able to regulate water intake and determine when to sprout or stay dormant Growth inhibiting 4. Abscisic Acid Produced in mature leaves, dormant buds, and seeds Effects: Inhibits cell elongation Inhibitsamylase secretion by Aleuron layer Promotes production of storage compounds Promotes leaf senescence 5. Ethylene Gas released from plant Effects: Interacts with the 3 growth promoting hormones to regulate cell size and shape If cells grow too fast then the cell wall isn't strong enough to support Promotes abscission of leaves fruits and flowers Promotes fruit ripening ❏ Growth from Seed Requires + Breaking of Dormancy Combinations of Internal/External Factors Internal External Hormones Sunlight Stored food Temp. Absorption water Day lengths Embryo swelling Soil moisture *Seed contains: Seed coat(s), embryo, stored food +As seed coats crack: Radicle (1st root) → grows down Shoot (stem + leaves ) → grows up +Cotyledons emerge “embryonic leaves” 1. Cotyledon (monocot) 2. Cotyledons (dicot) ➢ Seedling plant + Results of mitosis/cytokinesis (cell reprod.) Increase in cell size +Internal Development: Plant Cells → Plant Tissues→ Plant Organs ❖ Plant Nutrition +Essential Elements (nutrients) 16 in total C, H, O → from CO2 + H2O +13 Soil Nutrients (minerals) Absorbed dissolved in H2O through roots, follow pathway with H2O +Macronutrients (6): require more than 1 gram Nitrogen (N): Component of proteins, nucleic acids, coenzymes, chlorophyll Potassium (K): Enzyme activator, open/closing of leaf stoma, ionic balance of cells Phosphorus (P): nucleic acids, ATP, coenzymes, phospholipids Calcium (Ca): cell walls, regulator of membrane and enzyme activities, membrane permeability Sulfur (S): proteins, coenzymes Magnesium (Mg): enzyme activator, chlorophyll +Micronutrients (7): trace elements less than 0.1 gram Molybdenum (Mb): nitrogen fixation/absorption Copper (Cu): activator/component of many enzymes Zinc (Zn): activator/component of many enzymes Manganese (Mn): enzyme activator, chloroplasts membranes, oxygen release from chloroplasts Chlorine (Cl): ion balance, oxygen production during photosynthesis Boron (B): membrane structure, nucleic acid synthesis Iron (Fe): chlorophyll production Plant Transport Ch 38 +Movement of Water and Solutes in plants Water (Soil Nutrients) Food (Carbohydrates Hormones) Xylem Phloem +Importance of Water: Photosynthesis Support for plant organs Conduction Cell elongation Nearly all chemical reactions Avg. plant cell → 90% water +Solvent for most substances Solution: mixture of +2 compounds Solvent: compound in solution, usually in greater quantity, usually liquid Solute: compound in solution in lesser quantity, usually dissolved ❏ Physical Properties of Water +Polar molecule overall charge neutral +Hydrogen bonding each water molecule is Hydrogen bonded to 4 others “tight net” *Cohesiveness water molecules stick together tight *Adhesiveness sticks to other polar compounds (cellulose) *Temp. Stabilizer water can heat/cool things *Transport medium water flows in response to pressure/concentration Principles of Water + Molecule Movement Physical processes no energy expended 1. Bulk flow : movement of molecules in response to pressure/gravity, high to low 2. Diffusion : movement of molecules along a concentration gradient from high → low concentrations 3. Osmosis : diffusion of water across a selectively permeable membrane, water passes freely through membrane, solutes do not! Transpiration Ex. Each Individual Corn Plant requires apprx. 55 gallons of water 2% Normal Maintenance (cell elongation/photosynthesis etc.) 98% Transpired Transpiration : the loss of water (vapor form) exiting through stomata of leaves Photosynthesis Leaf Transpiration ❏ Guard Cell Pair: Function: Regulate stomatas; controls water loss Closed→ low in water/ keeps water and oxygen in, CO2 out Open → guard cells full of water (turgid)/ water and oxygen out, CO2 comes in ● Mechanisms: 1. Daytime/Sunlight CO2 low in leaf 2. Guard cells “pump in” Potassium (ATP expended), changes solute(increase) and water concentration(decrease) 3. Water from Xylem moves by osmosis into guard cells → “turgid” (swell) 4. Guard cells swell and open stoma 5. “Pump out” potassium (ATP expended), water moves out, guard cells shrink, closed again Causes of Water Loss Evaporation Water concentration is lowered in mesophyll, which causes a “pull” of water molecules via osmosis Loss of water from leaf xylem, causes “pull” from stem xylem Root xylem “pulls” water from soil CAT Mechanisms: Once stomata opens, it then becomes a purely physical process, no ATP “Pulling” of water molecules one at a time C:Cohesion keeps water molecules together A:Adhesion water adheres to cellulose in walls T:Tension “pulling” due to water loss via evaporation from mesophyll Translocation Movement of solutes +Similarities between transpiration and translocation: Physical properties of water +Differences Trans L (food/solutes) Trans P (water/minerals) Bidirectional Unidirectional Phloem (short/fat tubes) Xylem (long/slender tubes) Must expenditure of ATP by Plant Sunlight energy (no ATP expenditure by plant) *Food dissolves in water; moved in a form of sucrose Source → Sink Site of excess carbohydrates Storage site/site where sugar is quickly needed Pressure Flow Hypothesis Phloem tissue Sieve tube members companion cells load/unload STMS (ATP expended) At Source: 1. Companion cells “pump” sucrose into STM’s (ATP expenditure) 2. As sucrose concentration increases in STM’s, water potential(pressure) goes down within STM 3. Adjacent xylem tissue has higher water potential than STM’s, water moves into STM’s by osmosis 4. BULK FLOW of Sucrose (higher pressure to lower pressure) At Sink: 1. Companion cells must unload sucrose (ATP expended) 2. Sucrose converted to starch for storage in root cortex 3. Without sucrose, water potential changes, higher water potential in STM 4. Water moves via osmosis from the phloem STM to the adjacent xylem *ATP spent only on companion cells from loading and unloading *No energy expended from movement Bulk Flow (pressure/potential diffs) Osmosis (water concentration diffs) Flowers + Sexual Cycle Flowers only found in angiosperms approx. 300,000 species ❏ Essential processes of Sexual Reproduction occur within flower Meiosis/Cytokinesis: diploid to haploid Syngamy(fertilization) haploid to diploid “Ideal Flower” 4 sets of highly modified leaves in whorls at tip of modified stem Highly modified, Shortterm, Shoot system Diagram +Calyx and Corolla are “sterile” modified leaves Calyx: Protection of unopened bud Corolla: attract pollinators +Androecium + Gynoecium are “fertile” modified leaves Androecium (all stamens): “male household” male portion of flower, production of pollen (sperm) Gynoecium (all pistils): “female household” eggs are produced, female gametes +Sporophyte Generation (2N) Pedicel, Receptacle, 4 sets of modified leaves are 2n 4 sets of modified leaves arise from the receptacle +Gametophyte Generation (1N) Pollen (sperm) Egg Sexual Cycle ➔ Male side: Pollen formation within formation of stamen Anther: bilobed structure with 2 pollen chambers per lobe +Pollen diagram +Each 2N microscopic mother cell produces four 2celled pollen gametophtye Pollination +Self Pollination: Transfer within same flower/same plant Low genetic Diversity +Cross Pollination Transfer of pollen between plants +Pollinating Agents Wind Water Animals Sexual Cycle ❖ Female Side +Ovule = future seed Enclosed within ovary of pistil (carpel) 1 to many per ovary +Ovule attached to central axis of hollow ovary or to the ovary wall Ovules are always “enclosed” +Within ovule there is a single large 2N cell Called Megaspore Mother Cell (diploid structure ) *Embryo Sac is within Nucleus and Integuments inside ovary of pistil Syngamy: 1n egg + 1n sperm = 2n Zygote(single cell)(fertilized egg) +Pollen “germinates” Tube cell produces pollen tube Generative cell (1n) divides by mitosis/cytokinesis to produce two 1N sperm Pollen tube enters micropyle, digests nucellus Tip of pollen tube diagram Pollen tube enters one synergid , releases its contents, synergid ruptures, tube nucleus degrades, 2 sperm released into the large central cell Micropyle closes (seals up) pollen is trapped Double Fertilization 1n egg + 1n sperm = 2n Zygote(single cell)(fertilized egg) 1n sperm + 2 (2N) central nuclei (polars)+ 3N (1 °) Primary endosperm cell Post Fertilization: (within ovule) 2n zygote → mitosis +cyto = Multicellular 2n embryo 3n primary → mitosis + cell = multicellular 3n endosperm (nutritive tissue for embryo) endosperm cell Ovule with 2n zygote matures into seeds within 2n embryo Ovary of pistil matures, enlarges with sugar and water into a fruit with enclosed seeds Seed Dispersal (enclosed in fruit) Mechanism Wind Water Animals Seed Germination Seed with 2n embryo → period of Dormancy → Broken by combo of environmental and internal factors *END OF MATERIAL FOR EXAM NUMBER 2
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'